Apparatus for bright annealing tubes



INVENTOR ATTORNEY! May 29, 1934. c. T. PAUGH 1,960

APPARATUS FOR BRIGHT ANNEALING TUBES Filed June 8, 1931 4 Sheets-Sheet 1 can/6; mag

May 29, 1.934. c. T. PAUGH APBARATUS FOR BRIGBT ANNEALING TUBES Filed J ne. 8, 1931 4 Sheets-Sheet 2 a arr/es a I I m I Y M) BY ATTORNEY May 29, 1934. I 4 1 PAUGH 1,960,453

APPARATUS FOR BRIGHT ANNEALING TUBES Filed June 8, 1931 4 Sheefi-Sheeh 5 w w /yw a w l 91%) v ATTO RN EY- 5 May.29,- 1 934. Y c. T. PAUVGH 7 1,950,453

APPARATUS FOR BRIGHT ANNEALING TUBES Fil ed June 8. 1951 4 Sheets-Sheet 4 INVENTOR ATTORNEY;

Patented May 29, 1934 APPARATUS FOR BRIGHT ANNEALING TUBES Charles T. Paugh, Detroit, Mich., assignor'to Wolverine Tube Company, Detroit, Mich., a corporation of Michigan I Application June 8, 1931, Serial No. 542,982

14 Claims.

This invention relates to an apparatus for annealing tubes and the like and more especially to an apparatus for bright annealing copperv tubes.

' vide an'apparatus of this nature in which tubes and the like can be annealed while being continuously carried through the apparatus.

Another object of this invention is to provide an apparatus of this nature which is simple in construction and which may be produced, operated and maintained economically. Still another object of the invention is toprovide a device 'ofthis character in which means is provided for conditioning the'atmosphere surrounding the tubes or other work during the annealing process so as to prevent opzidization or other discoloring of the work,

The several objects, advantages and novel details of construction of the invention will be made more apparent as this description proceeds, especially when considered in connection with the accompanying drawings, wherein Figure l is a side elevational view of an anzs'nealing apparatus constructed in accordance with this invention; I

Figure 2 is a horizontal longitudinal section through the furnace section of the annealing device;

Figure 3 is a transverse sectional view through the furnace taken substantially on the plane indicated by line 33 in Figure 2;

Figure 4 is-an enlarged sectional view through the cooling section taken substantially on the plane indicated by line 4-4 in Figure 1;

Figure 5 is an enlarged sectional view through the equalizing unit taken substantially on the plane indicated by line 5-5 of Figure 1;

Figure 6 is a fragmentary sectional elevational view showing the means for conditioning the gas introduced into the conveyor tubes;

Figure 7 is a detail sectional view showing the expansionjoint for the conveyor tubes be tween the equalizing zone unit and the cooling tank unit;

Figure 8 is a transverse sectional elevationa view through the tube feeding mechanism;

Figure 9 is an end elevational view of the tube feedingmechanism, and

Figure 10 is an enlarged detail sectional view taken substantially on the plane indicated by line 10 -1Q inFigure 2. Referring now particularly to thedrawings wherein like reference characters indicate like parts, it will be noted especially from Figure 1,

The invention has as one of its objects to prothat the apparatus comprises a tube feeding mechanism or unit 10, a furnace unit 11, a heat equalizing zone unit 12, and a cooling tank unit 13.

As seen more particularly from Figures 2 and 3, the heating furnace unit comprises a rectangular elongated furnace chamber suitably supported by supporting members 14, the outer walls of the furnace chamber being formed of insulating material such for instance, as Sil-o-celbrick 15. A layer of Sil-o-cel powder 16 may be placed on top of the furnace if desired.

The interior of the furnace chamber is lined with brick indicated by the reference character 17. I

The upper electric heating elements 18 are suspended from the ceiling of the furnace cham- 'ber, being connected to tiles 19, the reference character 20 indicating the electric conduit for supplying current thereto. This is introduced into the heating chamber through a protective casing 21.

, The lower electric resistance heating elements 22 are supported on the floor of the furnace chamber, the reference character 23 indicating the conduit for supplying current thereto, this conduit being introduced into the furnace through'a protective casing 24.

The tubes, bars or other stock to be annealed are conducted through the furnace chamber through conveyor or guide tubes 25, which are supported at spaced points throughout the length of the furnace, preferably by means of alloy steel supports 26 extending transversely of the furnace chamber and fixed in the opposite walls thereof. 1 As seen most clearly in Figure 10, the conveyor tubes 25 as they emerge from the ends of the furnace are held between the pair of clamp plates 27 and 28, the clamp plate 27 being in the form of an angle bar fixed to the furnace wall. Bolts 29 passing through these clamp plates act to draw the plates together to clamp the conveyor tubes 25 therebetween.

After. passing out of the furnace the stock being annealed passes through the heat equalizing zone unit 12 which is shown more especially in Figure 5, comprising an elongated chamber substantially rectangular in cross section, the walls of which are insulated with Sil-o-cel brick insulation 30. Extending transversely through the chamber 31 of the equalizing zone unit are supports 32 having spaced recesses or notches 33 to receive and support the conveyor tubes 25. The space between the conveyor tubes 25 within the chamber 31 is preferably filled with copper chips and the like 34. This copper acts as a conductor for the heat between adjacent tubes so as to maintain a uniformity of heat throughout the series of conveyor tubes. As mentioned, the walls at the top, bottom and sides of the heat equalizing zone unit are insulated. With this construc tion the temperature of the tubes as they leave the furnace unit is substantially maintained throughout the equalizing zone but permitted to gradually decrease in the manner desirable in annealing.

In Figure 4 the cooling tank unit is illustrated in cross section. This cooling tank comprises an elongated chamber substantially rectangular in cross section, water being introduced thereinto through an inlet conduit 36, the reference character 37 indicating the overflow pipe. Extending transversely of this chamber at intervals longitudinally thereof are supports 38 similar to the supports 32 provided with recesses 39 for supporting the conveyor tubes 25. ,The body of these supports may be and preferably are, provided with apertures 40 to permit the free circulation of water through the cooling chamber unit.

Inasmuch as there is considerable longitudinal expansion and contraction between the sections of the conveyor, I provide each conveyor tube with an expansion joint such as illustrated in Figure 7, this expansible joint being located in each conveyor tube between the equalizing zone and cooling tank as shown in Figure 1.

In Figure 7 it will be noted that the adjacent ends of the sections of the conveyor tubesare indicated by the reference characters 25' and 25", the section 25' having a reducer sleeve 41 threaded thereon, this reducer having a threaded engagement with a sleeve 42 upon which a cap sleeve 43 is threaded. An asbestos and graphite packing 44 is located around the conveyor tube section 25" and between the cap sleeve 43 and the end of sleeve 42. The structure permits relative longitudinal movement between the tube sections 25' and 25" but prevents a leakage of the gas within the conveyor tube. In order to insure the passage of the stock from the tube section 25' into the tube section 25" the end of the latter is preferably flared as indicated at 45 and the edge of the tube section-25' may also be rounded or bevelled as indicated at 46.

Gas is introduced into the conveyor tubes for the purpose of excluding air therefrom and also for the purpose of producing and maintaining a non-oxidizing atmospheric condition within these conveyor tubes. This gas is preferably introduced into the conveyor tubes at the juncture of the furnace unit and equalizing zone unit although obviously the gas may be introduced at any desired point throughout the length of these conveyor tubes.

It is frequently more convenient and economical to employ in this connection ordinary city gas but in practice it is found that city gas frequently contains a small amount of free air which will result in an oxidization of the tubes.

To overcome this objection, the present invention contemplates the preheating at a high temperature of the gas and the addition thereto of a small amount of moisture which combines with the free carbon released as the result of the heating, this moisture combining with the carbon to produce carbon monoxide and hydrogen, thus' removing the free carbon from the mixture.

The moisture if not'subsequently removed from the gas is apt to slightly discolor the .StWk ba g annealed. Therefore, in accordance with my invention this moisture together with any remaining free carbon is removed in a chamber, cooled in any desired manner as, for instance, by circulating cooling water therethrough by means of finned tube coils. This reduces the temperature of the gas to a point where the excess moisture is condensed and may subsequently be drained oil. This condensate carries with it any remaining free carbon so that the gas when subsequently conducted to the tube is free from moisture at any temperature which will exist in the stock tube and is also free from carbon and free air.

The structure for accomplishing this purpose is illustrated in Figures 2 and 6 and particularly the latter figure. From Figure 2 it will be seen that the'furnace is provided with a conduit or tube 4'7 extending longitudinally therethrough. This is the gas preheating tube. At the left hand or inlet end the tube has connected thereto a water inlet pipe 48 controlled by a needle valve 49 by means of which a controllable amount of water is introduced into the gas preheating tube. If desired, a sight opening 50 is provided so that the amount of water being introduced may be readily determined.

This water mixes with the gas and as the gas is heated to an extremely high temperature, the water vaporizes and mixes with the free carbon released upon heating the gas to combine therewith in producing carbon monoxide and hydrogenin the manner previously explained.

At the other end of the furnace, I provide a chamber 51 into which the gas from the preheating tube 47 is discharged and in this chamber I locate a cooling coil 52, such for instance, as a finned tube coil, through which water is circulated by means of conduits 53. This sufficiently cools the gas to condense the excess moisture which may be drawn off through a drain cook 54 located in the bottom of chamber 51. An outlet conduit 55 extends downwardly into the chamber and. connects with a header 56 extending transversely of the equalizing chamber as indicated in Figure 1. This header is provided with a plu rality of branch conduits 5'7 corresponding in number to theconveyor tubes 25 and connected tothese conveyor tubes to supply the pre-conditioned gas thereto. Each conduit 5'7 may be provided with a valve 58.

The feeding means for the tubes is best illustrated in Figures 8 and 9 and as shown comprises an upper set of rotary driving .wheels 59 and a lower opposed set of driving members 60. The driving members 59 are provided with periheral Wedge shaped grooves 61 and the lower drivin members are provided with similar shaped grooves 62. The stock is engaged between these opposed V-shaped or wedge shaped grooves, the stock being herein indicated as a tube by the reference character T. By forming the engaging faces of the feeding membersV-shaped or wedge shaped, stock of various size within given limits may be fed by the same feeding mechanism as will be apparent. 1

The lower driving members are mounted on a shaft 63 which is rotatably journaled in bearing blocks 64 vertically slidably mounted in ways 65 formed in a supporting frame 66. The lower driving members 60 are fixed for rotation with the shaft 63 so that they will be positively driven by the rotation of this shaft. The vertical position of 'the bearing block 64 and consequently of thes aft 63 is limited in the downward direction by means of an adjustable stop 67. The upper driving wheels 59 are mounted upon a shaft 68 being keyed thereto by a key 69. While these driving members 59 are adapted to rotate with the shaft 68 a clearance is left between the shaft and the drivingmembers as illustrated in Figure 8. The ends of the shaft 68 are mounted in bearing blocks-70 slidably mounted in ways 7'1 in the frame members 66. A spring 72 is interposed between each pair of bearing blocks at the ends of the shaft, this spring acting to maintain the lower bearing block 64 in engagement with its adjustment stop 6'7 and also acting to raise the other bearing block 70 and consequently the shaft 68. The vertical location of shaft 68 is regulated by means of an adjusting screw 73 located at each end of the frame.

Each of the upper feeding members 59 is urged downwardly by means of a pressure roller '74 mounted on the end of an arm 75 pivoted at its end as at 76, the otherend of the lever having a spring 77 connected thereto, the spring being anchored as at '18 to the frame 66. These pressure disks '74 permit a relative movement between the corresponding feed member 59'and its shaft 68 equal to the amount of clearance between the shaft and the feed member. This permits each of the upper feed members to adjust itself to the accommodation of tubes or stock of varying sizes or diameters, it being understood that slight variations occur in the size of the stock being fed through the device, thus making it impossible to fix each of the driving members 59 tightlyhround its shaft 68.

The stock after it passes between the feedmembers 59-60 enters the adjacent ends of the conveyor tubes 25 and then passes through the furnace, then through the equalizing zone unit and then through the cooling tank. After a length of stock has passed beyond the feeding rolls it is fed onwardly through the device by the next succeeding length of stock, the ends of the conditions existing in the several units of the described, a heating chamber, a heat equalizing chamber, a cooling chamber, a stock guiding member extending through said chambers, and means for causing the stock to travel through said guide member.

2. In an annealing apparatus of the class described, a heating chamber, a heat equalizing chamber connected thereto, a cooling chamber associated with said heat equalizing chamber, a tubular guide member extending throughsaid chambers, and' feeding means for feeding the stock through said guide member.

3. In an annealing apparatus of the class described, a heating chamber, -a heat equalizing chamber connected thereto, a cooling chamber associated with said heat equalizing chamber, a tubular guide member extending through said chambers, feeding means for feeding the stock through said guide member,'and means producing and maintaining a non-oxidizing atmospheric condition in said guide member.

4. An annealing apparatus for copper tubes, bars and the like comprising, a heating chamber, a heat equalizing chamber, and a cooling chamber arranged in end-to-end relation, a guide tube extending through said chambers, and stock feeding mechanism located adjacent one end of said heating chamber for feeding the stock to be annealed through said guide tube.

5. An annealing apparatus for copper tubes,

bars and the like comprising, a heating chamber, a heat equalizing chamber, and a cooling chamber arranged in end-to-end relation, a guide tube extending through said chambers, stock feeding mechanism located adjacent one end of said heating chamber for feeding the stock to be annealed through said guide tube, and means for producing and maintaining anon-oxidizing atmospheric condition in said guide tube.

6. An annealing apparatus for copper tubes, bars and the like comprising, a heating furnace, electric heating elements arranged in said furnace, a heat equalizing chamber, a cooling chamber, means for circulating a cooling medium through said cooling ,chamber, a tubular guide member extending substantially continuously through said chambers, and means for feeding the stock to-be annealed through said guide member.

7. An annealing apparatus of the character described comprising, an elongated heating chamber, electric means for heating said chamber, an elongated heat equalizing chamber having one of its ends connected to one end of said furnace,

a cooling chamber, means for circulating a cooling medium through said cooling chamber, a stock guiding tubular member extending through said heating chamber, equalizing chamber and cooling chamber and open at its opposite ends, means for maintaining a non-oxidizing atmospheric condition within said tubular member, and means adjacent the furnace for feeding stock to be annealed into and through said tubular member.

8. In an annealing apparatus of the character described, an electric heating furnace, a heat tion to said furnace, stock guiding tubes extending through said furnace and equalizing cham-' ber, means in said equalizing chamber for insulating said tubes to effect a slow cooling of the stock which passes therethrough from the furnace, a cooling chamber, means for cooling said chamber, and means extending through said cooling chamber for receiving and guiding the stock while preventing direct contact therewith of the cooling medium.

9. In an annealing apparatus of the character described, a heating chamber, a heat equalizing chamber, and a cooling chamber, said chambers being arranged in end-to-end relation, a plurality of tubular guide members through which the stock is fed, said guide members extending through said chambers to subject the stock to the conditions existing therein while maintaining the stock completely enclosed, and feeding means arranged at one end of the furnace for introducing the stock into and feeding the same through said guide tubes.

10. In an annealing apparatus of the character described, a heating chamber, a heat equalizing chamber and a cooling chamber, stock guiding tubes extending successively through said chambers, means for introducing the stock to be annealed into and feeding the same through said guide tubes, said heat equalizing chamber including means for insulating said tubes from the atmosphere and means for establishing a heat conducting connection between adjacent tubes, for the purpose set forth.

4 11. In an annealing apparatus of the character described, a heating chamber, a second chamber, a tubular guiding member extending through said heating chamber and said second chamber, and means possessing a high degree of thermal conductivity surrounding said guiding member within said second chamber.

12. In an annealing apparatus of the character described, a heat equalizing chamber, a plurality of tubular guide members extending through said chambers, and means in said heat equalizing chamber establishing a heat conducting connection between adjacent tubular members.

13. In an annealing apparatus of the character described, a tubular guide member, and means for supplying a non-oxidizing gas to said tubular guide member, saidmeans including a source or illuminating gas, means for moistening said gas, means for heating said moistened gas, and means for cooling said moistened gas to precipitate the excess moisture therefrom. I

14. In an annealing apparatus of the character described, a heating chamber, a heat equalizing chamber and a cooling chamber, stock guiding members extending successively through said chambers, means for introducing the stock to be annealed to and feeding the same along said guiding members, said heat equalizing chamber including means for insulating the stock from the atmosphere, and means for establishing a heat conducting connection between adjacent strips of stock.

' CHARLES T. PAUGH. 

